Abstract: The aim of this study was to provide basis for the further understanding of the functions of vsp Y1 and vsp Y2 genes of Mycoplasma bovis Inner Mongolia isolates（NM2012）. Two sets of primers were designed based on the published vsp Y1 and vsp Y2 genes of Mycoplasma bovis and used to amplify the vsp Y1 and vsp Y2 genes of NM 2012 isolate. The obtained sequences were cloned and sequenced. The nucleic acid sequence of vsp Y1 and vsp Y2 genes of NM 2012 isolate were compared with that of the related published genes respectively to identify their similarity. The similarity with other published or deduced amino acid,conserved domain, trans-membrane structure, signal peptide, lipoprotein and epitope of the amino acid sequences deduced by vsp Y1 and vsp Y2 genes were predicted by using online bioinformatics tools, respectively. The results showed that the size of vsp Y1 and vspY2 genes of NM 2012 isolate were 1 029 and 804 bp, respectively, and both of them contained complete open reading frames（ORF）, encoding 342 and 267 amino acids, respectively. The similarity of nucleic acid sequence between vsp Y1 gene of NM 2012 isolate and others related genes ranged from 99.4% to 100%, and that of the deduced amino acids sequence ranged from 98.6% to 99.7%. The similarity of nucleic acid sequence between vsp Y2 gene of NM 2012 isolate and others related genes were 100%. Based on the bioinformatics analysis results obtained in this study, it could be deduced that vsp Y1 was a potential virulence factor.